Open ChildForm from another ChildForm in MDIParent

juzjess · October 4th, 2007, 03:52 PM

I'm working on WinForm application and created MDIParent form. I have no problem launching child form from the MDIParent form itself, however I couldn't figure out a way to launch ChildForm2 from ChildForm1. Here's what I have in ChildForm1 code:

Code:

        private void btnChild2_Click(object sender, EventArgs e)
        {
            frmChild2 Child2 = new frmChild2();
            frmParent frmParent = new frmParent();
            frmParent.IsMdiContainer = true;
            Child2.MdiParent = frmParent;
            Child2.Show();
        }

Please advice.

samjudson · October 4th, 2007, 04:09 PM

Surely if you want them to have the same parent then you don't want to create a new parent form.

Code:

frmChild2 c2 = new frmChild2();
c2.MdiParent = this.MdiParent;
c2.Show();

/- Sam Judson : Wrox Technical Editor -/

juzjess · October 4th, 2007, 04:25 PM

Thank you so much for your answer, that's work!

However, I have one more quick question:
Let say when Child2 is launch, I want to check if there's any other child form still open and close them.

Code:

        public void childClose()
        {
            foreach (Form childForm in this.MdiChildren)
            {
                childForm.Close();
            }
        }

        private void btnChild2_Click(object sender, EventArgs e)
        {
            childClose();
            frmChild2 Child2 = new frmChild2();
            Child2.MdiParent = this.MdiParent;
            Child2.Show();
        }

samjudson · October 4th, 2007, 04:29 PM

You haven't actually asked a question?

But you are aware that that code will try to close the form you are currently running the code in as well?

/- Sam Judson : Wrox Technical Editor -/

juzjess · October 4th, 2007, 04:34 PM

Yes, I wanted to close Child1 or any other child form that still open when Child2 is launch, but the code that I have doesn't close it. How do you do that?

samjudson · October 4th, 2007, 04:37 PM

Code:

foreach (Form childForm in this.MdiParent.MdiChildren)

/- Sam Judson : Wrox Technical Editor -/

juzjess · October 4th, 2007, 04:46 PM

thank you!

juzjess · October 4th, 2007, 04:52 PM

It still doesn't work. It close all the child forms, but instead of opening Child2 as a child form, it open as an independent form instead. Do you know a way for when Child2 is launch, it close all the "other" child form and open Child2 as a childform?

samjudson · October 5th, 2007, 01:28 AM

I can only assume that because you are closing the current form before opening the new form that the MdiParent property is being blanked. Check this is not null before you are using it.

You could try this:

Code:

frmChild2 Child2 = new frmChild2();
Child2.MdiParent = this.MdiParent;
Child2.Show();

foreach (Form childForm in this.MdiParent.MdiChildren)
{
  if( childForm != Child2 ) childForm.Close();
}

/- Sam Judson : Wrox Technical Editor -/

juzjess · October 9th, 2007, 08:28 AM

That function work when I call from another child form, thank you! However, I actually want to use a user control inside of that frmChild1 and call frmChild2 so with this.mdiParent doesn't work. I try with frmParent.MdiParent, but it doesn't work either. Please advice!